SpringBoot 注册Servlet三大组件【Servlet、Filter、Listener】

由于SpringBoot默认是以jar包的方式启动嵌入式的Servlet容器来启动SpringBoot的web应用，没有web.xml文件。

//注册三大组件
//servlet
@Bean
public ServletRegistrationBean myServlet(){
    ServletRegistrationBean registrationBean = new ServletRegistrationBean(new MyServlet(),"/myServlet");
    return registrationBean;
}

//filter
@Bean
public FilterRegistrationBean myFilter(){
    FilterRegistrationBean registrationBean=new FilterRegistrationBean();
    registrationBean.setFilter(new MyFilter());
    registrationBean.setUrlPatterns(Arrays.asList("/hello","/myServlet"));
    return registrationBean;
}


//Listener
@Bean
public ServletListenerRegistrationBean myListener(){
    ServletListenerRegistrationBean<MyListener> registrationBean = new ServletListenerRegistrationBean<>(new MyListener());
    return registrationBean;
}